52,091 research outputs found
Isolated Galaxies versus Interacting Pairs with MaNGA
We present preliminary results of the spectral analysis on the radial
distributions of the star formation history in both, a galaxy merger and a
spiral isolated galaxy observed with MaNGA. We find that the central part of
the isolated galaxy is composed by older stellar population (2 Gyr) than
in the outskirts (7 Gyr). Also, the time-scale is gradually larger from 1
Gyr in the inner part to 3 Gyr in the outer regions of the galaxy. In the case
of the merger, the stellar population in the central region is older than in
the tails, presenting a longer time-scale in comparison to central part in the
isolated galaxy. Our results are in agreement with a scenario where spiral
galaxies are built from inside-out. In the case of the merger, we find evidence
that interactions enhance star formation in the central part of the galaxy.Comment: 7 pages, 2 figures. Proceedings of the EWASS-2015 special session
Sp3, accepted for publication in Special Issue "3D View on Interacting and
Post-Interacting Galaxies from Clusters to Voids" of open access journal
"Galaxies
Anomalous high energy dispersion in photoemission spectra from insulating cuprates
Angle resolved photoelectron spectroscopic measurements have been performed
on an insulating cuprate Ca_2CuO_2Cl_2. High resolution data taken along the
\Gamma to (pi,pi) cut show an additional dispersive feature that merges with
the known dispersion of the lowest binding energy feature, which follows the
usual strongly renormalized dispersion of ~0.35 eV. This higher energy part
reveals a dispersion that is very close to the unrenormalized band predicted by
band theory. A transfer of spectral weight from the low energy feature to the
high energy feature is observed as the \Gamma point is approached. By comparing
with theoretical calculations the high energy feature observed here
demonstrates that the incoherent portion of the spectral function has
significant structure in momentum space due to the presence of various energy
scales.Comment: 5 pages, 3 figure
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